The present disclosures are directed to an improved approach for achieving high-performance light extraction from a Group III-nitride volumetric LED chips. More particularly, disclosed herein are techniques for achieving high-performance light extraction from a Group III-nitride volumetric LED chip using surface and sidewall roughening.
In making LED chips, improving the performance of light extraction from the material is an important design consideration. In some situations patterning or roughening of certain surfaces can improve light extraction. And, in some situations the materials used in making LEDs (e.g., GaN, Sapphire, SiC) are scribed, sawed, cleaved and otherwise manipulated during process such that those processes result in patterning or roughening of the surfaces of the LED device and/or surrounding structures. However, when Group III-nitride materials (e.g., gallium nitride) is used, traditional cleaving or other manipulations do not necessarily result in patterning or roughening of the surfaces of the LED device and/or surrounding structures, and other techniques are called for in order to achieve high-performance light extraction.
Moreover, the manufacture of Group III-nitride volumetric LED chips might involve cleaving along certain selected planes (e.g., c-plane, m-plane), and certain specific processing techniques (e.g., laser scribing) might be used with the Group III-nitride material, thus further demanding advances in the techniques to produce Group III-nitride volumetric LED chips that exhibit high-performance light extraction from surface and sidewall roughening.
Therefore, there is a need for an improved approach for achieving high-performance light extraction from Group III-nitride volumetric LED chips. In the approach to achieve high-performance light extraction from surface and sidewall roughening when using Group III-nitride materials, many discoveries have been made, which discoveries and embodiments thereto are disclosed in detail below.